The present invention relates to control system and method for controlling acceleration slip of a vehicle by performing fuel cut and ignition timing control.
Japanese Patent Provisional Publications No. S63(1988)-309745 and No. H1(1989)-147127 show acceleration slip control systems for controlling acceleration slip by manipulating a fuel cut system and an ignition timing system.
When a fuel cut and an ignition timing shift are performed simultaneously on the occurrence of acceleration slip, a combination of a delayed fuel injection in the fuel cut cylinders to which the fuel supply has been cut off and an ignition timing retard tends to cause an incompletely burned fuel residue which in turn causes after burning due to exothermic reaction in a catalytic converter of the exhaust system, and overheat of the catalyst. In order to prevent the after burning and the overheating of the catalyst, the acceleration slip control systems disclosed in these documents are arranged to inhibit a fuel enrichment (or an increase of fuel supply quantity) during an engine output reduction control. When, for example, the fuel supply to one cylinder is cut off in a six-cylinder engine, these conventional systems inhibit the fuel enrichment to the remaining five fueled cylinders.